LED is a kind of green and environment-friendly light source with the advantages of high luminous efficiency, less power consumption, long life, high reliability, easy to control, etc. LED is commonly used as a backlight source in mobile phones or as an indicator light in other devices, but its applications are not limited to this. LED also has promising prospect for its development and presents big market potential in the aspect of lighting application. Recently, LED has obtained so great development as to start its commercial application in lighting field and will gradually replace the existing fluorescent lamps. That is, the high-power LED lamp will become a practical lighting equipment for a variety of applications as it is economical and stable.
However, most of the existing high-power LED lamps must be provided with an external or separate power and/or control device to protect the LED lamps from burning up due to insufficient heat dissipation or unstable driving voltage and inconstant current.